Dental instrument.



No. 769,758. PATENTED SEPT. 13, 1904. J. MILLS.

DENTAL INSTRUMENT.

APPLICATION FILED JUNE 20, 1903.

NO MODEL.

74? 71 @2315 88 4/1 V Q14 ("0r ./QWM W Patented September 13, 1904.

PATENT OFFICE.

JOHN MILLS, OF BRANTFORD, CANADA.

DENTAL INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 769,758, datedSeptember 13, 1904.

Application filed June 20, 1903.

To all whmn it may concern.-

Be it known that I, JOHN MILLs, D. D. 8., of the city of Brantford, inthe county of Brant, Province of Ontario, Canada, have invented certainnew and useful Improvements in Dental Instruments, of which thefollowing is a specification.

The object of my invention is to devise an attachment for a dentalengine whereby the rotary motion of the engine may be converted into areciprocating rectilinear motion for operating, cleaning, and burnishingtools or other instruments for which such a motion is desirable; and itconsists, essentially, of a hollow casing adapted for attachment to thehandpiece of a dental engine, a rotary part journaled within the casingand provided with a spindle for connection with the rotating spindle ofthe handpiece, a reciprocating tool socket-piece slidably supported inthe casing, a grooved cam formed on or connected to the rotary part, anda projection on the tool socketpiece adapted to fit the cam-groove, thewhole being constructed in detail substantially as hereinafter morespecifically described and then definitely claimed.

Figure 1 is a side elevation, partly broken away, of the instrument.Fig. 2 is a sectional elevation of the central or main part of thecasing, showing the rotary part of the instrument journaled thereon.Fig. 3 is a sectional elevation showing the method of adjusting thebearing of the rotary part of the instrument. Fig. L is a sectionalelevation of the main part of the casing and the tool socket-piece, theview being taken on a plane at right angles to Fig. 1.

In the drawings like letters of reference indicate corresponding partsin the different figures.

Referring particularly to Fig. 1, it will be seen that the casing of theinstrument comprises three partsa central or main part A, a forwardportion B, and a rear portion (J. The partC of the casing is so shapedand proportioned as to lit the handpiece of an ordinary dental engine.For this purpose it also has a notch a cut in its end. This portion (Jis detachably connected to the main portion Serial No. 162,404. (Nomodal.)

' A, preferably by being screwed thereon, as shown. The forward portionB of the casing slips over the main portion, as shown, and is held inposition by means of a screw 1). The main portion of the casing hasoppositely-set cone-bearings D and E formed therein. With these hearingsare engaged the cones F and G, connected to the rotary part H of theinstrument. This rotary part is extended into a spindle 0, which isadapted for connection with the spindle of the handpiece of the dentalengine.

It will be noted that the cone G is formed integral with or rigidlysecured to the spindle 0, whereas the cone F is screwed onto thespindle, so as to be adjustable thereon, its end being provided with aslot for engagement by a screw-driver. It is also preferable to use ajam-nut L. Means are thus provided for taking up any wear of thebearings. The cone F, it will be noticed, is provided with a cylindricalportion in which is cut a peripheral cam-groove I. This cylindricalportion, it will be noticed. is inclosed within the main part of thecasing, but the latter has a notch (i cut at one side, exposing thecam-groove.

A tool socket-piece J is slidably supported in the forward part B of thecasing and has a finger K formed thereon, which fits within the notch (Zof the main part of the casing. On this linger is formed or secured apin (2, which enters the cam-groove I. This pin might of course be aroller, if necessary, to reduce friction.

"hile the tool socket-piece may be of any description, I prefer to formit as shown in Fig. 1, a hole being bored therein threaded at its innerend. This enables what are gen erally known as cone-socket instrumentsto be connected therewith.

From the construction described it is evident that rotary motionconveyed to the spindle 0 of the rotary part of the instrument willthrough the medium of the cam-groove be converted into reciprocatingrectilinear motion of the tool socket-piece J. Thus a new tool movementis provided for dental operations which is particularly adapted forcleaners, burnishers, and other prophylactic instrurnents. The movementmight also be applied to dental pluggers, though not to such advantage.Y

While the construction of the casing is that which I prefer, as givingthe readiest access When necessary to the working parts, yet

other constructions might of course be employed.

Changes might also be made in the precise construction of the partsWhich produce the conversion of motion.

What I claim as my invention is- 1'. In adental instrument a main casinghaving a pair of oppositely-set cone-bearings formed therein; incombination with a rotary part having cones thereon adapted to engagethe hearings, one of the cones being longitudinally adjustable on thesaid rotary part; a cylindrical extension of one of the cones having aperipheral cam-groove formed therein, the casing being notched at oneside to expose the cam-groove; a front casing sleeved over one side toexpose the cam-groove; a tool socket-piece slidably carried inthe frontcasing; a finger on said socket-piece fitting the notch in the maincasing; and a pin on said finger engaging the cam-groove, substantiallyas described.

Brantford, June 10, 1903,.

JOHN MILLS. In presence of- A. C. HARDY, I. BAXTER.

